Estimation of Dispersed Glaciation Shrinkage Under Climate Change

Abstract

We propose a new method of estimating the shrinkage of glaciers over a wide area under conditions of changed climate. The method can be also used to quantitatively estimate the presence of glaciers under past climatic conditions, in mountainous areas where they are currently absent. The method is based on the use of statistical parameters of the distribution of glaciers by altitude zones, according to vertical distance from the climatic equilibrium line altitude (CELA). The method was used for the Pskem River basin (tributary of the Chirchik River, Western Tien-Shan) where glaciation has been extensively studied. Data are available for several glacier inventories for the basin for different time periods from 1957 to 2010. The number of glaciers for the part of the basin considered in the studies decreased by 16 percent during that period. Mean summer air temperature and annual precipitation were used as climate indicators characterizing ablation and accumulation on glaciers. Data of several meteorological stations located in the Pskem River basin were used to document these climatic characteristics. We estimated shrinkage of glaciers over the area for increases of summer air temperature of 0.5 - 2°C.